In short, it's just too early to tell. Just because the RIRs ran out of addresses, it doesn't mean that the LIRs have yet (the ISPs).
Based on my experience as a network engineer at an ISP, the following is happening already:
Small ISPs and ISPs that have not been in the business for a long time* have either run out or are on the verge of doing so. They are doing the following:
* Purchasing legacy IPv4 addresses from enterprises with
* Deploying CGN-like solutions for their end-customers if their end-customers are residential users.
Larger ISPs and older ISPs with allocations from ye old pre-RIR days continue to hold addresses and are often able to free large quantities of addresses from old deployments. Mind you, a lot of public IPv4 space have been "wasted" on infrastructure addressing, and management of devices that were not even connected to the internet. Devices such as modems, DSLAMs, CPEs and similar.
One could easily speculate that the business of ISPs will be severely affected in the future, as customers will go to the old providers that have plenty of v4-space available at the cost of newer players who followed the RIR regulations of only applying for the address space they needed based on relative short-term predictions.
If you are a registered LIR you will see a flood of SPAM from so-called IP brokers who are trying to purchase unused IPv4 space in hope of selling this to LIRs in need. That market will probably become quite desperate in the coming years.
Oh, and by the way, I see no evidence that IPv6 deployment is taking any noticeable speed.
*) Long as in they were in the game when classfull allocations were made.